Guide bar shogging mechanism for a warp knitting machine

ABSTRACT

The guide bars of a warp knitting machine are moved longitudinally in response to stored information scanned by a programming device and converted to electrical control signals. A cam follower linked with each guide bar is engaged alternatively by two cams which are moved in a direction toward and away from the cam follower in response to the control signals. The cam follower moves back and forth between the faces of the two cams in synchronization with the main machine drive.

United States Patent Schneider et al.

[451 July 25, 1972 GUIDE BAR SHOGGING MECHANISM FOR A WARP KNITTING MACIHNE Inventors:

Assignee:

Filed:

Appl. No.:

Harald Schneider; Cornel Wlcha, both of Augsburg, Germany Karl MayerTextilmaschinenfabrik GMBH, Obertshausen Offenbach, Germany Jan. 15,1971 Foreign Application Priority Data 1 References Cited UNITED STATESPATENTS 3,456,461 7/1969 Offermann et ..66/86 3,478,543 11/1969 Faninger..66/86 3,089,322 5/1961 Bruce 8! al.. ..66/86 X 3,006,170 10/1961Chapuis ....66/154 X 2,416,933 3/1947 Lynam et al. ..66/154 PrimaryExaminer-Ronald Feldbaum A!trneyl(urt Kelman [5 7] ABSTRACT The guidebars of a warp knitting machine are moved longitudinally in response tostored information scanned by a programming device and converted toelectrical control signals. A cam follower linked with each guide bar isengaged alternatively by two cams which are moved in a direction towardand away from the cam follower in response to the control signals. Thecam follower moves back and forth between the faces of the two cams insynchronization with the main machine drive.

10 Claims, 4 Drawing Figures g e a llllll,

Patented July 25, 1972 3 Sheets-Sheet 1 [W EV T0125 HnRm.) smutuea wlcrmHGENT Patented July 25, 1972 3,678,711

3 Sheets-Sheet 2 AGEN Patented July 25, 1972 3,678,711

5 Sheets-Sheet 5 FIG. 4

IN'VEN T0125 HARRLD SCHNEIDER CORNEI. wlcmq HGENT GUIDE BAR SI-IOGGINGMECHANISM FOR A WARP KNITTING MACHINE this invention relates to warpknitting machines, and particularly to guide bar shogging mechanismwhich are programcontrolled.

Cam operated shogging mechanisms are still largely controlled by patternchains or pattern wheels. Cam elements on the moving chain or wheelengage a cam follower linked to each guide bar. When a complex patternis to be knitted, many individual cam elements must be brought intosequential engagement with the cam followers during each pattern repeat.Such patterns cannot always be made by means of pattern wheels, thepattern chains employed must be very long so as to require much laborfor setting up and substantial machine downtime for each change from onepattern to another.

It has recently been proposed to control the shogging motion of a guidebar by levers mounted on a common shaft. Ends of the levers directedtoward the guide bars have stepped faces, and the position of a guidebar is determined by the angular position of an engaged lever and theselected engaged step. Because of the necessarily small number of stepson each lever, many levers need to be associated with each guide bar ifa wide variety of longitudinal guide bar positions is called for.

The levers are set according to signals provided by a programming devicein which as many channels must be provided as there are levers, and theinformation carrier employed must be equipped correspondingly. Theprogramming unit significantly increases the bulk of the knittingmachine and of associated devices, and is not practical in a Raschelknitting machine having a multiplicity of guide bars.

The primary object of the invention is the provision of a guide barshogging mechanism automatically controlled by a program source whichconsists of relatively few, simple, and compact elements, and can beoperated by an information carrier provided with a minimum number ofchannels.

Another object is the provision of such a mechanism in which patternchanges can be achieved quickly and with little cost.

According to the more specific aspects of this invention, a warpknitting machine is provided with a guide bar shogging mechanismincluding a cam arrangement which cooperates with a cam followeroperatively connected with the guide bar for simultaneous movement. Aprogram source generates programmed control signals in synchronizationwith the machine drive. The cam arrangement includes two cam elementswhose respective cam faces constitute portions of a cam track extendingin a general direction. A first moving device connected to the machinedrive causes relative reciprocating movement of the cam elements and ofthe cam follower in the general direction of the cam track and therebymoves the cam follower back and forth along the track in alternatingengagement with the faces of the two cam elements. A second movingdevice responsive to the control signals of the program source moves thecam members in a direction transverse to the cam track directionrelative to each other.

Other features, additional objects, and many of the attendant advantagesof this invention will readily be appreciated as the same becomes betterunderstood by reference to the following detailed description ofpreferred embodiments when considered in connection with the appendeddrawing in which:

FIG. I is a fragmentary, side-elevational and partly diagrammatic viewof a warp knitting machine of the invention;

FIG. 2 shows a modification of a portion of the device of FIG. 1;

FIG. 3 illustrates yet another modification of a detail in the device ofFIG. 1 on a larger scale; and

FIG. 4 diagrammatically illustrates the horizontal position of a camfollower roller in the apparatus of FIG. 3 as a function of time duringoperation.

Referring now to the drawing in detail, and initially to FIG. I, thereis shown only as much of an otherwise conventional knitting machine asis necessary for an understanding of the invention. The structureillustrated is limited practically to the shogging machanism for oneguide bar, and it will be understood that much of the illustratedapparatus is duplicated as many times as there are guide bars whoselongitudinal movement needs to be controlled.

A reader 1 for punched paper tape is driven by a timing belt or chain insynchronization with the main drive shaft of the machine, not shown, andcontrols a selector switch assembly 2 controlling twelve circuits whichrespectively energize the coils of twelve solenoid valves 20, 21.

A rocker arm 3 pivotally mounted on the machine frame is oscillated by aradial cam 4 continuously rotated in synchronization with the main driveshaft and the reader 1. The rocker arm 3 is held in engagement with thecam 4 by a tension spring 5 attached to the machine frame.

The rocker arm 3 carries two stacks 6,7 of six pneumatic actuatingmotors each, the motors being arranged in series so that the piston rodsand cylinders of four actuating motors in each stack are fixedlyfastened to respective cylinders or piston rods of adjacent motors. Oneterminal motor in each stack is attached to the rocker arm 3 by atransverse bar 3a.

The free end portion 3b of the rocker arm 3 is approximately U-shaped,and compression springs 6a interposed between each stack 6,7 and thetransverse or bight part of the rocker portion 3b normally drives thepiston rods inward of the as sociated cylinders to reduce the stack toits minimum length or contracted condition. The valves 20,21 controlflow of compressed air from a non-illustrated source, such as a manifoldon a tank, to the cylinders of the stacks 6,7 so as to expand each motorby a length differential which is of fixed magnitude for each motor.When deenergized, the solenoid valves vent the associated cylinders tothe atmosphere, thereby permitting the vented motors to be contracted bythe springs 6a.

The piston rods of terminal motors in the stacks 6,7 which are remotefrom the bar 3a pass through openings in the bight part of the rockerarm portion 3b and are attached to respective ratchet bars 8longitudinally guided along opposite faces on the leg parts of therocker portion 3b by non-illustrated dovetail grooves and ribs. The endsof the bars 8 remote from the attached piston rods carry elongated camelements 9 which extend from each bar 8 toward the other bar and partlyoverlap in a longitudinal direction. The teeth 10,11 of the bars may beengaged by respective pawls or detents 12,12a which are pivoted on therocker portion 3b and biased toward engagement with the associatedratchet teeth by an interposed compression spring 13. Stops 14,15fixedly mounted on the machine frame alternatively engage the detents12,12a as the rocker 3 approaches the ends of its oscillating stroke andlift the detents from the engaged ratchet teeth.

The cam face of each element 9 has two angularly offset portions 22,24for cooperation with a cam follower roller 23 on a guide bar shogginglever 16. The latter is connected to a partly illustrated guide bar 17by a hinged link 19, as is conventional, and held in engagement with oneof the cam elements 9 at all times by a tension spring 18 interposedbetween the guide bar 17 and the machine frame.

Each cam face portion 24 is circular approximately about the pivot axisof the rocker 3 so that the guide bar 17 does not move coursewiserelative to the knitting needles and other non-illustrated andconventional knitting implements of the machine while the cam follower23 engages a cam face portion 24 while the cam elements 9 participate inthe oscillating movement of the rocker 3. The cam face portion 22 isobliquely inclined relative to the circular arc of the associated camface portion 24 in a direction having a major radially in ward componentrelative to the arc.

The afore-described apparatus operates as follows:

As long as the main drive of the knitting machineoperates, punched papertape is drawn through the reader 1 in synchronization with the knittingoperation, and the valves 20,21 admit compressed air to individualcylinders in the stacks 6,7 or release air from the cylinders. Theoverall length of each stack 6,7 is thereby varied in stepscorresponding to the strokes of the several piston rods in the stack. Inthe illustrated embodiment, the six motors in each stack change thelength of the stack by l, 1, 2, 2, 4, 4 units respectively, the positionof the roller 23 on the lever 16 being chosen in such a manner that theguide bar 17 is shifted one needle spacing relative to thenon-illustrated needle bar of the knitting machine when the length of astack 6,7 attached to a cam 9 engaged by the roller 23 changes by oneunit. Other dimensional relationships of the individual motors differingby a factor which is an integral power of 2 may obviously be resorted toif desired, and a binary stroke ratio of 122:4:8: 1 6:32 may be chosenfor achieving a maximum range of longitudinal guide bar movement withsix series-connected pneumatic motors in each stack. The spacing of theratchet teeth 10,11 on each bar 8 corresponds to one unit of lengthchange in the stacks 6,7.

When the rocker arm 3 is moved clockwise from the position in FIG. 1 byrotation of the cam 4 and the action of the spring 5, the detent 12engages the ratchet teeth to lock the bar 8 and the initially disengagedcam 9 associated with the teeth 10 in a position previously set by theswitch assembly 2 on the stack 6. The cam follower roller 23 moves alongthe cam face portion 22 toward the pivot axis of the rocker arm 3, andthe guide bar 17 is moved to the left.

The cam follower roller 23 then reaches the face portion 24 of thelocked cam element 9 and rolls along the cam face portion to a stopwhile the angular position of the lever 16 remains practically unchangedso that the guide bar 17 may perform its swinging motion. Atapproximately the same time, the detent 12a is disengaged from theratchet teeth 11 as the rocker arm 3 reaches the end of its clockwisestroke, and the cam element 9 not engaged by the cam follower roller 23may be shifted by its stack 7 of actuating motors to a differentposition in response to signals from the paper tape reader 1. Assumingthat no such signals are given, and the length of the stack 7 remainsunchanged, the guide bar 17 is shifted toward the right, while the camfollower 23 moves over the cam face portion 22 toward the illustratedposition during counterclockwise movement of the arm 3, and thelongitudinal position of the guide bar 17 remains the same to permitswinging motion of the guide bar, while the roller 23 moves downwardover the face portion 24 from the position seen in FIG. 1.

Depending on the manner in which the length changes in the stacks 6,7are programmed, the cam 9 not engaged by the cam follower may be movedtoward or away from the cam track constituted by the several cam faceportions 22,24 and extending generally longitudinally of the arm 16. Theguide bar 17 may therefore be moved in steps of any desired lengthwithin the combined range of the several motors in each stack, andsuccessive steps may be made in the same direction or in oppositedirections. The cam element 9 engaged by the cam follower 23 is lockedby the associated detent 12,12a while the other element is released foradjustment of its position.

The modified apparatus shown in FIG. 2 is identical with that describedwith reference to FIG. 1 as far as not illustrated. It is equipped witha support element 3 almost identical with the rocker arm 3, but fixedlymounted on the machine frame. It carries stacks 6,7 of pneumatic motorswhich set the positions of ratchet bars 8 and of cam elements 9' fixedon the bars and having transverse terminal face portions 22corresponding to the afore-described face portions 22 in FIG. 1. Theydiffer from the cam elements 9 in the configuration of their faceportions 24.

Detents 12,12a are mounted on the support element 3' and biased by aspring 13 toward engagement with ratchet teeth 10,11 on the bars 8. Acam follower roller 23 cooperates with the cam face portions 22,24 andis mounted on a shogging lever 16 for moving a guide bar 17 as describedabove. The lever 16' is shifted longitudinally by a radial cam 25 whichengages a cam follower roller 25a secured on the end of the lever 16remote from the guide bar 17 by a pin 25d. The pin projects from thelever 16 into a slot 25b in a bracket 25c fixedly mounted on the machineframe. The slot 25b is elongated approximately logitudinally of thelever 16 in all operative angular positions of the latter. The cam 25 isconnected to the nonillustrated main drive shaft of the knitting machineby a timing belt or chain, as described with reference to the cam 4 inFIG. 1. Steps 26,27 are mounted on the lever 16' and move toward andaway from the detents 12,12a during rotation of the cam 25.

The apparatus illustrated in FIG. 2 operates in the same manner asdescribed above with reference to FIG. I. The rolling motion of the camfollower 23 along the cam face portion 22,24 in FIG. 1 is caused by theoscillations of the rocker arm 3. The analogous movement of the camfollower along the cam face portions 22,24 in FIG. 2 is produced bylongitudinal movement of the lever 16', the cam face portions 24' beingcontoured so that the guide bar 17 stands still while the cam follower23 engages these face portions.

It will be appreciated that FIGS. 1 and 2 are not drawn to scale, andthat the links 19 which hingedly connect the lever 16' to the guide bar17 are long enough so that the longitudinal movement of the lever 16'has no significant effect on the longitudinal position of the guide bar17. The detents 12,12a are released from the ratchet teeth 10,11 whenthe stops 26,27 and the attached lever 16' reach the end of their commonstroke.

Whereas two guide bar movements are performed with the guide barshogging mechanism illustrated in FIGS. 1 and 2 during each revolutionof the cams 4 or 25, four movements are available in otherwise unchangeddevices with modified cam elements, as shown in FIG. 3 for an apparatusidentical with that of FIG. 1 as far as not specifically statedotherwise.

The cam elements 9",9' have oblique terminal cam face portions identicalwith the afore-described cam face portions 22 and not requiring furtherdescription. The cam face portions 24 are replaced by stepped faces,each step having a face portion circular approximately about the pivotaxis of the rocker arm 3. The cam face portion 28a of the cam element 9"which is remote from the free end of the cam element is nearer the pivotaxis than the face portion 28b which extends to the end of the camelement, and the two face portions are connected by a steeply inclinedsurface. In the other cam element 9", the cam face portion 29a adjacentthe free end of the cam element is nearer the pivot axis than the othercam face portion 29b.

During a cycle of engagements of the cam follower roller 23 with the camelements 9" and 9", the associated guide bar, not itself seen in FIGS.'3and 4, makes an overlap from the right to the left when the roller 23engages the cam element 9" and an overlap from the left to the rightwhen the roller engages the cam element 9". When the roller travelsalong the cam face portions 28a, 28b, 29a, 29b, no significant movementof the guide bar takes place.

FIG. 4 diagrammatically illustrates the movements of the roller 23during one cycle of cam movements. The roller initially engages the camface portion 280 and moves at first upwardly, as viewed in FIG. 4, tothe cam face portion 29a. This results in the underlap movement 30 shownin FIG. 4. The initially opposite direction of the overlap stage isinsignificant because the yarn guides are not located behind the latchneedles at this time. The actual underlap is caused by movement of theroller 23 from the cam face portion 28b to the portion 29a. After thisunderlap movement from 28a to 29a, the roller 23 stands still whiletraveling over the face portion 29a.

The roller 23 then continues its movement from the cam face portion 29ato the face portion 29b whereby an overlap 31 over one needle to theright is caused. The direction of movement now is reversed and the stepsdescribed above are repeated in opposite order, that is, the roller 23moves continuously from the face portion 29b to the face portion 28b tocause an underlap 30a, it further moves from the face portion 28b to theface portion 28a to produce an overlap 31a from the right to the left.

With the arrangement of cam elements illustrated in FIG. 3,predetermined and constant overlaps from the right to the left and fromthe left to the right alternate with underlaps which may be of differentlength.

While the invention has been described with reference to an apparatus inwhich the cam arrangement cooperating with the cam follower roller 23 isconstituted by two cam elements, more than two may be resorted to in amanner obvious from FIG. 3. A single stepped cam face 28a,28b or 29a,29bmay be replaced by faces of individual carns individually set byassociated stacks of hydraulic motors. The illustrated two-camarrangement, which will be found satisfactory for most purposes,combines simplicity of structure with adequate versatility.

A pattern change is achieved in the guide bar shogging mechanism of theinvention by simply changing the tape in the reader, an operation whichrequires virtually no time, and it may not even be necessary to stop themachine. A programming unit other than that illustrated and describedmay be used without otherwise changing the apparatus, and the use ofmagnetized tape in cooperation with a suitable reader is specificallycontemplated. Other variations will obviously suggest themselves tothose skilled in the art.

It should be understood, therefore, that the foregoing disclosurerelates only to preferred embodiments of the invention, and that it isintended to cover all changes and modifications of the examples of theinvention herein chosen for the purpose of the disclosure which do notconstitute departures from the spirit and scope of the invention setforth in the ap pended claims.

What is claimed is: g

1. In a warp knitting machine including drive means, an elongated guidebar, and a guide bar mechanism for longitudinally moving said guide bar,said mechanism including cam follower means operatively connected tosaid guide bar for simultaneous movement, and cam means engaging saidcam follower means, the improvement which comprises:

a. programming means for generating programmed control signals inresponse to operation of said drive means,

1. said cam means including two cam members,

2. said cam members having respective cam faces constituting respectiveportions of a cam track extending in a general direction;

b. first moving means operatively connected to said drive means forcausing relative reciprocating movement of said cam members and of saidcam follower means in said direction and for thereby moving said camfollower means back and forth along said cam track in alternatingengagement with said cam faces; and

c. second moving means responsive to said control signals for movingeach of said cam members in a direction transverse of said generaldirection relative to the other cam member.

2. In a machine as set forth in claim 1, said second moving meansincluding actuating means associated with each cam member for moving theassociated cam member in integral multiples of a unit step.

3. In a machine as set forth in claim 2, said actuating means eachincluding a plurality of actuating members series-connected in saidtransverse direction, and operating means for expanding and contractingeach of said actuating members in said transverse direction by adifferential which is one of said multiples.

4. In a machine as set forth in claim 3, the differentials associatedwith a plurality of said actuating members differing by a factor whichis a power of 2.

5. In a machine as set forth in claim 1, a common support carrying saidcam members, said first moving means including means for angularlymoving said support about an axis remote from said cam track.

6. In a machine as set forth in claim 1, said faces having respectiveportions obliquely inclined relative to said predetermined direction andtransverse to each other.

7. In a machine as set forth in claim 6, faces having respective otherportions parallel to said general direction.

8. In a machine as set forth in claim 1, locking means locking each cammember against movement in said transverse direction when the cam facethereof is engaged by said cam follower means.

9. In a machine as set forth in claim 8, releasing means releasing saidlocking means when said cam member is not engaged by said cam followermeans.

10. In a machine as set forth in claim 9, a common support carrying saidcam members, said first moving means including means for angularlymoving said support about an axis remote from said cam track, said camfaces having respective first portions approximately circularly arcuateabout said axis and respective second portions obliquely inclinedrelative to the associated first portions and transverse to each other,said second moving means including actuating means associated with eachcam member for moving the associated cam member in integral, binarymultiples of a unit step, said actuating means each including aplurality of actuating members series-connected in said transversedirection, and operating means for expanding and contracting each ofsaid actuating members in said transverse direction in. response to saidcontrol signals.

1. In a warp knitting machine including drive means, an elongated guidebar, and a guide bar mechanIsm for longitudinally moving said guide bar,said mechanism including cam follower means operatively connected tosaid guide bar for simultaneous movement, and cam means engaging saidcam follower means, the improvement which comprises: a. programmingmeans for generating programmed control signals in response to operationof said drive means,
 1. said cam means including two cam members, 2.said cam members having respective cam faces constituting respectiveportions of a cam track extending in a general direction; b. firstmoving means operatively connected to said drive means for causingrelative reciprocating movement of said cam members and of said camfollower means in said direction and for thereby moving said camfollower means back and forth along said cam track in alternatingengagement with said cam faces; and c. second moving means responsive tosaid control signals for moving each of said cam members in a directiontransverse of said general direction relative to the other cam member.2. said cam members having respective cam faces constituting respectiveportions of a cam track extending in a general direction; b. firstmoving means operatively connected to said drive means for causingrelative reciprocating movement of said cam members and of said camfollower means in said direction and for thereby moving said camfollower means back and forth along said cam track in alternatingengagement with said cam faces; and c. second moving means responsive tosaid control signals for moving each of said cam members in a directiontransverse of said general direction relative to the other cam member.2. In a machine as set forth in claim 1, said second moving meansincluding actuating means associated with each cam member for moving theassociated cam member in integral multiples of a unit step.
 3. In amachine as set forth in claim 2, said actuating means each including aplurality of actuating members series-connected in said transversedirection, and operating means for expanding and contracting each ofsaid actuating members in said transverse direction by a differentialwhich is one of said multiples.
 4. In a machine as set forth in claim 3,the differentials associated with a plurality of said actuating membersdiffering by a factor which is a power of
 2. 5. In a machine as setforth in claim 1, a common support carrying said cam members, said firstmoving means including means for angularly moving said support about anaxis remote from said cam track.
 6. In a machine as set forth in claim1, said faces having respective portions obliquely inclined relative tosaid predetermined direction and transverse to each other.
 7. In amachine as set forth in claim 6, faces having respective other portionsparallel to said general direction.
 8. In a machine as set forth inclaim 1, locking means locking each cam member against movement in saidtransverse direction when the cam face thereof is engaged by said camfollower means.
 9. In a machine as set forth in claim 8, releasing meansreleasing said locking means when said cam member is not engaged by saidcam follower means.
 10. In a machine as set forth in claim 9, a commonsupport carrying said cam members, said first moving means includingmeans for angularly moving said support about an axis remote from saidcam track, said cam faces having respective first portions approximatelycircularly arcuate about said axis and respective second portionsobliquely inclined relative to the associated first portions andtransverse to each other, said second moving means including actuatingmeans associated with each cam member for moving the associated cammember in integral, binary multiples of a unit step, said actuatingmeans each including a plurality of actuating members series-connectedin said transverse direction, and operating means for expanding andcontracting each of said actuating members in said transverse directionin response to said control signals.